Foot for artificial limbs



March 30, 1937. G. LANGE 2,075,583

FOOT FOR ARTIFICIAL LIMBS Filed Aug. 51, 1935 Gpb Lieb Lange,

@25% MMM/Imm* Patented Mar. 30, 1937 'f- UNITEDI STATES PATENT oFFlc-E 3Claims.

My invention relates to improvements in feet for articial limbs,particularly those of the pneumatic type, and it consists in thecombination, constructions and arrangements herein described andclaimed.

An object of my invention is to provide a foot for an artificial limbwhich is durable, and which will flex in walking in a manner to simulatethat of the natural foot.

A further object is to provide a pneumatic foot which may be easilyinflated, but in which the means for ination is concealed. y

A further object is to provide a device of the type described in whichthere is a central metallic core which takes the main weight of theuser, but works in cooperation with a rubber form so as to givestability and exibility.

A further object of the invention is to provide a device of the typedescribed having a metal core which is so disposed that it may have alimitated rotative movement at a point approximating the ankle of thenatural foot and also a similar movementJ in connection with the rubberform at a point where the toes of the natural foot flex in the action ofwalking.

A further object of the invention is to provide a device of the typedescribed which is composed of relatively few parts, and which thereforeis not easily liable to get out of order.

My invention is illustrated in the accompanying drawing forming part ofthis application, in which:

Figure 1 is a central sectional view through the foot and the shoe, and,

Figure 2 is a perspective view of the core.

In carrying out my invention I provide a rubber form like that shown inthe drawing. This form, as will be noted, has a base portion 3, a toeportion ffl, an instep portion 5, ankle portions 6 and a heel portion l,all these portions being formed integrally. At the top of the ankleportions are integrally inwardly extending flanges 8. The interior ofthe form is hollow, as shown. At 9 I have indicated an integral rubberboss above the heel and at Il) a similar smaller boss.

The core is made of metal, preferably aluminum, and is of the shapeshown in the drawing. It consists of a body portion I I having asubstantially cylindrical extension I2, which is provided with a recessof a shape to conform to' the contour of the boss 9.

An angular extension I3 has an expanded end III provided with a recessto conform with and receive the boss IIJ. The top of this core isflattened, as shown at I5, and is p-rovided with threaded lugs I6, whichextend through the flanges 3 and through the bottom I'I of a cupshapedmember I9 being held by nuts 20. The core is recessed to receive a valvestem 2I and is provided with an air passage 22 communicating with thehollow form. The member I9 is preferably riveted to a shin plate 23, asshown in the drawing. The pneumatic foot is completed by the shoe 24,which in this instance is shown as oxford type.

From the foregoing description of the various types of the device theoperation thereof may be readily understood. Access to the valve stem 2Imay be had from an opening (not shown) in the shin guard, or in someother place which is covered. The foot is inflated after the manner of apneumatic tire until it assumes the proper form. Now in the act ofwalking it will be 0bserved that if the heel strikes the ground rst, asit does when most people walk, the greater portion of the weight willcome on the core body, the boss 9, and the heel of the shoe. There is aslight pivotal movement to bring the foot to the ground and the foot isflexed at the base of the toes as the movement proceeds.

This flexure is taken care of by these two bosses 9 and I0, since theypermit a bending movement as the walking proceeds. The flexing of thepneumatic foot is aided by the hollow construction, while at the sametime the fact that the foot is distended with the air tends to returnthe foot to natural form immediately after the flexing action is over.

I claim:-

1. A pneumatic foot for artificial limbs comprising a hollow resilientfoot-shaped body, a solid core within said body, said core having adownwardly extending substantially cylindrical portion provided with arecess, and an integral angularly disposed portion provided with arecess at the end thereof, said resilient foot-shaped body havingintegral bosses exten-ding upwardly from the bottom of said foot-shapedbody and arranged to enter the recesses in said core, and means forsecuring the top of the resilient footshaped body to the top of thecore.

2. A pneumatic foot for articial limbs comprising a hollow resilientfoot-shaped body, a metal core within said body, said metal core havingan air passage and being provided with a substantially cylindricalportion having a recess and an angularly disposed portion provided witha flared end, and a recess in said end, said resilient body having aboss near the heel to enter the recess in the cylindrical portion of thecore,

and a second boss near the ball of the foot-shaped body arranged toenter the recess in the angularly extending portion of the core, an airValve disposed in the air passage of said core at one end of thepassage, the opposite end of the passage communicating with the spacebetween the core and the inner Wall of the foot-shaped body, and meansfor securing the top of the core to the resilient foot-shapedbody.

3. A pneumatic foot for artificial limbs comprising a hollow resilientfoot-shaped body having inwardly extending anges, a metal core, acup-shaped member disposed abo-ve said flanges, means for clamping theflanges between the core and said cup-shaped member, a shin platesecured to said cup-shaped member, said metal core having a centralbore, land a laterally extending air passage communicating therewith, avalve stem disposed in the bore in said core, said core having asubstantially cylindrical portion, the axis of the cylindrical portionextending through the heel, said core having an angular integralextension provided with a downwardly turned are-d end, the cylindricalportion of the core and said flared end having recesses, and in tegralbosses carried by the foot-shaped body for entering said recesseswhereby a slight pivotal movement of the core at each of said bosses ispermitted.

GOTTLIEB LANGE.

